I used StackTimer, before it changed its name to JungleTimer. Since StackTimer required an internet connection, the author was able to make it so StackTimer is now broken, forcing me to use JungleTimer. Problem is JungleTimer is asking me to pay money for full features. The free version does not include red/blue buffs.

So I'm looking for a different jungle timer that can time dragon, baron, both red/blue buffs, and doesn't cost money. Any recommendations?

If you can't find one you can turn on the in game timer and type in when each buff/objective was taken.
Blue/Red -- 5 mins
Dragon -- 6 mins
Baron -- 7 mins (4 min buff duration)

Ex: (11:04 (player name /champion name): 17:04 dragon

Do what pro players do:
Keep track of it in your head.

Gotta agree with Retched here.

It's better to just memorize the respawn times of the buff/objective camps. Eventually, you'll also develop an innate sense of when something will respawn. (ex. a gut feeling that dragon or buffs will respawn since you took it earlier w/o looking at a clock/timer).

Support players and junglers are... encouraged to help state when the buffs/dragon/baron will respawn.

A good tip on baron respawn: the buff last 4 minutes. so you can look at the buff to know exactly when it will respawn (each 1/4th of the buff is one minute). When the buff expires, there are 3 minutes left until baron respawns.

Turn on time indicator on chat. Ping a buff as it's dying.

The LJTD from www.ljtd.net is like the JungleTimer, just with more feature and completely free to use and Open Source.

Maybe you should also check it out, in case you are still searching for a working Jungle Timer.