I used Betternet for some time about a couple of years ago and speeds weren't terrible but it was very unreliable - disconnected every few minutes and I seem to recall it didn't have a killswitch so you may want to take precautions in that respect.
I don't know what sort of usage you want but if not too much then Windscribe's free 15gb a month might be sufficient.
Using the browser extension for a couple of days now. So far no ads or connection problems. Speed seems better than Zenmate too, which I used before.
Sadly only two servers in the free version, one in the US and one in the UK. I don't know if the desktop variant has more of them.
Would not trust this. I think that logging is a big privacy concern for this one! Plus the fact , stated earlier in this post that connections can be cut off is also a big nono. Better go for the free 50gb a month windscribe installer ( or extension ) or cyberghost free. Far better options. IMHO.