Question Help moving app to another phone

[Judslat]

Hi all, this may be a slightly long post so forgive me

A long time back there was the DJI Phantom 2 quadcopter (P2 for simplicity), and an App called the Litchi app and another called Ultimate flight (but we will concentrate on Litchi ), this app was written just for the P2.
Litchi no longer support the app as they have moved on to a newer version which sadly isnt compatible with the old P2 range.

I have a samsung S5 phone (rooted) on which the app is installed and working, so why am I here?

Well the app on install and first run sends a message to the servers at DJI.COM to validate the SDK and this is where the story starts

For this to happen the phone had to be connected to the internet, once done this was no longer repeated and the app would work fine with or without internet access ad infinitum.

Move forward to the point where DJI decided to switch off the validation server and the app when freshly installed can no longer verify itself and as such now wont work, I'm assuming that DJI in their infinite wisdom assumed that no one was using the P2 Litchi app or UF or wanted to use it, how wrong they were, there is a still a large number of P2 flyers.

I did contact Litchi support who said it was a DJI issue, DJI refused to answer any questions and would only say speak to Litchi (catch 22, wonder where that saying came from) any how Litchi wont offer any help as the app isnt supported, fair play as it was a free app at the time.

Here lies the question, I want to move the app from the old S5 to something newer such as an S7 or S8 etc (model isnt relevant) as the S5 phone is Rooted I installed Titanium backup and tried that, I googled a shed load about apps and where the data is stored but couldnt find anything and yes you guessed it when the backup is installed in another phone it tried to validate the SDK.

Im gonna go out on a limb and assume (feel free to call me an ass) that somewhere in the app folders there must be a file that is read when the app starts up to see if its been validated or similar, the same way once windows is activated it doesnt keep bugging you and if so it just works.

I really want to get this app working in one way or another as I know a lot of P2 flyers (yes most of us are over 50) so if anyone has any suggestions i would be eternally grateful.

Thanks in advance for any answers
PS im an old man so i may not answer any posts straight away but I will as soon as I can.
PSPS I hope i followed all forum etiquette correctly forgive me if I didnt
Jud

 

[SpookDroid]

Unfortunately, it isn't that simple. There are apps that can attempt to back up an app and its settings files to transfer to a new device, but these are seldom successful in the latter because most apps are now coded to encrypt that data and are usually digitally tied to a specific device ID (so even if you were to copy every bit in the files, the ID on the new device wouldn't match and the app wouldn't be able to function).

 

[Judslat]

Unfortunately, it isn't that simple. There are apps that can attempt to back up an app and its settings files to transfer to a new device, but these are seldom successful in the latter because most apps are now coded to encrypt that data and are usually digitally tied to a specific device ID (so even if you were to copy every bit in the files, the ID on the new device wouldn't match and the app wouldn't be able to function).

Thats a shame, but i guess its for the greater good, but lets say this, as its an app built for the long forgotten Android 4 and 5, would this level of encryption be in use? is there someway to find out where the files are written to when the app is installed, remember the phone is rooted so I have access to all the files as opposed to the usual few, or can the app be installed in something like an android emulator ( im really stretching this I know) such as Android SDK developer tools (again its amazing what google will tell you) and then run the app and see at what point the request is made, or even where the app files are installed to.

Thanks again for any help

 

[VidJunky]

Welcome to Android Central forums. One of the first things I considered when reading through your post was that you were rooted. Technically if you were able to identify and move the correct file to any other device, like a PC or laptop, the file would be moved unencrypted when saved to that device. Then it would come down to if the key contained in that file was a unique to that device key. Where the key references the device in some provable way. Some way that the program/app can check to see if X, whatever x would be, is true about the device. To be honest I really wouldn't expect it to work, otherwise there is no security to prevent the app from being shared without compensation to the developers. As it stands though what have you got to lose by locating the app's program folder on the device and copying the whole folder to the new device in place of whatever is there. If it fails you're still in the same position you're in and if it works then you're better. Is it a risk...? I guess only if you're not able to secure another installable copy with default folder content.

On a side note it turns out that catch 22 is a plot point introduced in a 1961 novel about a soldier who is trying to be found insane to avoid being redeployed to duty but by trying to be found unfit he is proving he's fit otherwise he wouldn't be trying to avoid it. The doctor in the book uses this phrase catch 22 without reference so from what I can find it is a totally made up plot point that caught on somehow and because the slang we use today to describe a situation of which there is no escape. Once the question was asked I had to know too.

Best wishes sorry if this wasn't much help.

 

[Madd62]

On a side note it turns out that catch 22 is a plot point introduced in a 1961 novel about a soldier who is trying to be found insane to avoid being redeployed to duty but by trying to be found unfit he is proving he's fit otherwise he wouldn't be trying to avoid it. The doctor in the book uses this phrase catch 22 without reference so from what I can find it is a totally made up plot point that caught on somehow and because the slang we use today to describe a situation of which there is no escape. Once the question was asked I had to know too.

Best wishes sorry if this wasn't much help.

Off Topic :
Didn't know that but heard of the Joseph Heller book.
Perhaps sometimes referred to also as the Klinger Option.
(that's MASHed up)

 

[Judslat]

Welcome to Android Central forums.

Thanks, you guys are a friendly bunch

To be honest I really wouldn't expect it to work, otherwise there is no security to prevent the app from being shared without compensation to the developers.

The App was free to users, so they probably didnt care if it was shared.

As it stands though what have you got to lose by locating the app's program folder on the device and copying the whole folder to the new device in place of whatever is there. If it fails you're still in the same position you're in and if it works then you're better. Is it a risk...? I guess only if you're not able to secure another installable copy with default folder content.

Im currently trying to root an S6 that i have spare, its being a pain though, I have a titanium backup so will see restoring via titanium works

On a side note it turns out that catch 22 is a plot point

Many thanks for looking this up its nice when forum users go that little bit extra

Best wishes sorry if this wasn't much help.

Oh you have been helpful bud, I'll see if i can sort out the S6 and will post back soon either with a yay or a "I give up but thanks all".

 

[Judslat]

Ok so im officially at the point of saying yep no chance of getting this to work, i managed to root the S6, simple enough with Odin and a file that was foiund via google, used Titanium restore function but its a no go. so im guessing as you guys have said there must be a file that is uniquely linked to the phone ID in some way.

Well its been a blast but im not wasting anymore time on it.

 

[SpookDroid]

Long shot, but over at XDA you may be able to find someone who's savvy enough to modify the APK to bypass the server check. And, of course, there's always the option to message the original developer/product manufacturer to see if they have or can come out with an updated option.