Here is a post from another forum I saved because I got this program with the thoughts of having 5 ROM's on the phone at the same time.
I use it. And I love it. Here's some instructions that I use when I set it up.
1. Set up phone ROM as it says when you first open the app.
2. To install a ROM press "install zip" and find the ROM you want then it will take you to a screen where you make sure and put check marks in "wipe system, wipe data, wipe cache" then select the ROM slot to install to. (It doesn't matter which one just select one not in use, should say ROM 1, 2, 3). Then it asks if you want to use ext4 or ext2. I use ext2 unless I know for sure the ROM supports ext4. Either one works fine for me.
3. To make sure its working pull down the notification bar and you will see an ongoing notification saying "installing system.img" or something like that. It will then go to "installing data.img" then "installing cache.img" then it will change to "unzipping (filename)". Then when its done it will say successfully installed (ROM name). This will take a long time.
4. If the ROM needs you to install Google apps such as in CM7 or other AOSP ROMs go through the same process but DO NOT put checks on any of the wipe options (the three you checked in the first installation of the ROM.) This will he fast since its only Google apps and not a whole ROM.
5. If you want a certain kernel install it the same way you did the Google apps without wiping anything (installing a kernel for sense ROMs is done the same way, no wipes on the system cache or data.) I always install a kernel because sometimes I find if I don't the ROM wont boot. I tried using the install kernel option at the bottom of the screen but I have had little success so I do it this way which works.
6. Now you are ready to select "boot ROM" in the main screen. Make a nandroid backup, although it doesn't backup your memory card which is where your ROMs except phone ROM are stored it is a good idea in case something goes wrong you can at least go back to your origional ROM and restart.
7. The first boot will seem like its taking forever because it will. Mine took around 8 to 10minutes. 8. If you want to flash a MOD into a ROM other than phone do not use clockworkmod recovery, just boot into phone ROM and install it like you did Google apps and the kernel.
9. That's all. You should be able to boot into multiple ROMs easier now.
10. To delete ROMs to install new ones I use a file manager to go into sdcard/bootmanager/ROMX and delete it just to be sure everything is gone for a clean install
It took me a bit to get used to but here's some things I figured out...
1. Obviously when you first install it says to "set up phone ROM " just press yes, this is so you can boot back to the ROM you have mainly on your phone.
2. Don't turn off the screen when you install a ROM into a slow or it will not turn back on.
3. ONLY FLASH THINGS IN CLOCKWORKMOD RECOVERY IF YOU ARE BOOTED INTO THE PHONE ROM AND ARE FLASHING FOR THE PHONE ROM. If you flash something in clockworkmod recovery while in another ROM other than Phone ROM you will bootloop and have to restore a nandroid.
4. It takes trial and error to perfect this app.
5. If something doesn't flash right and you bootloop then the try a different kernel or set of Google apps.
6. You must use the Google apps from the OMFGB guys for the OMFGB ROM or it will bootloop.
7. Patients is a vurtue. The installation takes a long time and will slow your phone down alwuite a bit so don't install a ROM when you need to use your phone a lot.
8. If it says you dont have enough space on the sdcard. Go into the LOST.DIR folder and delete everything. Its a worthless file with just lost files.
9. The sdcard ROMs take up a lot of space so have a 32gb card. They take at least 3.3 gigs I think.
And finally.... if you choose to help someone out ofbthe kindness of your heart and write a guide such as this use your computer because my thumbs hurt real bad now and I think I swyped a few grooves into my screen and probly have carpel tunnel now haha.
Well I hope I helped good luck and you will love this app once you get it down.
Boot Manager User Guide
I've not had the time to use this program yet but will be getting it started soon. Likely on my days off this week. I'm not sure of the GPS thing but I believe there is a fix for the GPS issues people were having.