For android try Tides, it does what it says on the tin plus you get a tidal curve so you can see the earliest and latest time to put in and take out if you know how much depth you need for your boat.
Scar I use absolute tides a lot for sailing and kayaking and a wee bit for the dinghy as well
Find it dead easy to use and it has a tidal atlas feature so you can see the set and drift of the tide in real (ish) time if that's of use to you
A brilliant app in my opinion