Anyone knows if there is already any service of "proxy" online LN wallet?

I mean, something that would work like this:

- I send, for example, 0.1BTC to their wallet (my deposit address) same as I do with an exchange.

- Now I have a 0.1BTC balance with them (not your keys, not your BTC... I know)

- Then, the service would let me send LN payments which they would route via their LN node and already established channels on my behalf and substract the amount (plus a fee, presumably) from my balance.

- A plus would also be the possibility of creating LN invoices and receiving payments in the same way above and an easy to use mobile phone APP.

Anyone?