Scrabble Timer Apps

The Apple app Zarf has an excellent built in clock for competitive Scrabble games, however, if you don't have Zarf, here are two excellent alternatives:
Wali Timer for android, developed by Wali Muhammad Khubaib
ChessClock for iOS, developed by Chess.com

Feature Comparison Between Zarf and ULU

Recently Apple has discontinued support for 32 bit apps with the latest version of their operating system, iOS 11. This means the much beloved iPhone and iPad app called Zarf no longer works on devices running iOS 11. Thankfully, Seth Lipkin has written a similar app called ULU available on the app store. In my opinion Zarf is still the best app but ULU comes a very close second. See a comparison of features below.

Feature	Zarf	ULU
Search pattern	Yes	Yes
Search anagram	Yes	Yes
Search build	Yes	Yes
Sort search results, length	Yes (increasing & decreasing)	Yes (increasing & decreasing)
Sort search results, alphabetical	Yes (increasing & decreasing)	Yes (increasing & decreasing)
Sort search results, novelty	Yes (increasing & decreasing)	No
Sort search results, probability	Yes (increasing & decreasing)	No
Sort search results, value	Yes (increasing & decreasing)	No
Multiple searches in one	Yes	No
Lexicon	Any (including CSW15)	Any (including CSW15)
Fast search as you type	Yes	Yes
Judge	Yes	Yes
Clock	Yes	No (see alternatives)
Compatible with iOS <11	Yes	Unknown
Compatible with iOS >=11	No	Yes
Compatible with android	No	No
32 bit application	Yes	No
64 bit application	No	Yes
Sanctioned for WESPA tournaments	Yes	Not yet
Cost	Free	Free