To be perfectly honest, I'm a little bit obsessed with Worthy Bonds.
The minimum buy-in (i.e., one single bond) is $10.
They aim to pay 5% interest come hell or high water.
You can cash out your bonds at any time.
They support small/local businesses.
Seriously, how could I not be obsessed?
I haven't downloaded their app--I just interact with them through their website--but the thought of seeing my interest grow from my phone is appealing, so we'll see what happens. Their website is sleek and efficient, as is their business model: loan cash to small businesses who can use inventory as collateral, making the loans much safer--"worthier," if you will--than standard loans. Charge more than 5% interest; profit. Everybody wins.
It's not quite Kiva, but it's a kick-ass compromise between high interest (relative to savings accounts) and decent ethics.
So sign up with Worthy Bonds for as little as $10, and get $10 free for you and me. Tell your friends, and get $10 when they sign up. Everybody wins!