At the beginning of my journey and haven't put a filter on my devices yet, partly because I'm not sure which to choose or where to start. I don't need anything super intense, just something that will block adult sites with a password (it will be set up so I'm not in possession of the password). Using an iPhone. Any ideas?
Haṣlaḥah to everyone

I don't have any specific suggestions but a peice of wisdom from Dov.



The best filter is the one you don't test - Dov

I can't speak for the exact idea of what you are looking for, but I have been delighted with techloq.

If you're near a TAG office, Iphone restrictions with a Gentech thingy they put on is free and pretty good. Better for blocking the browser completely than for filtering specific sites though. They can hold the password or write it down for someone else. MB Smart is also a decent option with a filtered browser. Then there are the heavier duty frum filters, Techloq, Gentech etc. 

Recommend calling a TAG office to schmooze about specific features of each one.

Definitely recommend calling a TAG office. Even if you don't live near one, if you call them they will be happy to talk it over with you (headquarters is the Lakewood office, I believe).
Personally, I'm thinking MB Smart would be your best bet. Great filter and can't beat the price.