Well, it looks good.... and having the source code out there.... help to give it more credibility. (I hate these wallets with proprietary source code) 
it is also listed on walletscrutiny, cause just having the source code in the open doesn't mean anything. you can't be sure that what you download from the app store is actually what you find in the source code posted in the open. (i have no affiliation with walletscrutiny and never used unstoppable wallet)That's correct. Also Unstoppable wallet is listed on Fdroid app store now. What that means is Fdroid bot takes open source code of Unstoppable wallet from github, compiles it and makes app available on Fdroid app store. There is no other way to get listed on Fdroid.