text message app total size growing bigger

[mrgigabyte]

i have a droid maxx with 4.4 kitkat and i have notice that as i use this my text message app textra it is growing in total size right now the total of this app is 10 mb and this is only one day of using it so i am wondering how big is it going to grow i have try looking in forums for this answer about this problem i even delete my text messages after i read it so i dont understand this with my old cell a razr maxx on jb this app did not get any bigger in size is this a problem with 4.4 or is because droid maxx does not use sd card i know this cell has 32 gb but just wondering about this , my email was growing in size also i use aquamail but at these it cleans it self so it gets to 30 mb and then once a day it goes back down to 10 to 12 mbs and then grows again but as these up and down is better then growing bigger and bigger

hopefully someone knows this answer

thanks mrgigabyte