Looking past the "closed source" thing for a second... It's great that they're "licensed" and all:
OWNR WALLET holds two licenses allowing us to exchange virtual currencies against fiat (FVR000645) and provide a virtual currency wallet service (FRK000559). For more details, feel free to check our Terms of Service.
But this is the bit that concerns me:
OWNR WALLET is a private limited company based in Estonia.
Not sure what legal recourse one would have regarding a company based in Estonia?
Additionally, the fees seem quite excessive... and a little vague:
Transaction Fees
The User agrees to pay OWNR the Transaction fee for each completed order. The fee makes $7 per order, regardless of the amount. We may also charge some percent of the transaction amount, which varies depending on the region and asset price volatility.
Noting of course that this for "fiat" transactions (not simply moving crypto in or out)
Also, the wallet has a limited number of countries that they are able to conduct fiat->crypto transactions with:
https://ownrwallet.freshdesk.com/support/solutions/articles/44001816455
I'm sure there will be "open source or not at all" users... but I wouldn't have any issues with users promoting this wallet.
Still, competition is healthy, so good on them... as with DaveF, I'd probably not use it... not because of the closed source thing, but simply because I don't need a "multicoin" wallet, and my current wallet solutions on desktop/mobile are adequate to my needs (and open source
)
Hard to put a firm number on "the dangers of using this wallet"... No better/worse than other multicoin offerings like Exodus/Jaxx/Coinomi would be my "rating".