The most important for mobile crypto wallet is to be non-custodial. I use both open source wallets like Samourai and BRD and closed source like Ownr. And I notice any differences.
The problem is that you might not notice any difference because it's a long con. The provider might be collecting backups of all the users' wallets an carefully watch if the BTC are getting more or less. He would have some staff to provide a good product etc. Then at some point he cashes out. He might even sell the product and then, a week later pull the rug and put blame on the buyer who paid him already on top of the loot.
I'm 100% confident that there are are project out there that are highly regarded by their users but ultimately the providers are psychopaths with no regards for the damage they will do when they pull the rug.
Hey giszmo, thanks a lot for your work. I am not a tech guy otherwise I would be helping you more. I am sharing your site with my closest friends to let them abandon everything which is not (reproducible) open source.
Listen, I have a question for you, if you would like to answer it: what is your current bitcoin storing set up? how do you make your coins secure? how about your keys and passphrases? etc.
I am all ears if you wish.