Strengths: Speed, spear. If you asked him, he would try to convey that he is good at everything, but end up giving some completely unintelligible speech that would just further confuse you.
Note: Does annoying people (or according to Katelyn, trolling while speaking in texting language) count as a strength or a weakness?
Personality: Energetic, acts like he's super awesome. Some tributes find him quite awesome and want to ally with him. Others *coughcoughbethanywakelingcough* find him quite annoying and may or may not try to rip his throat out.
Strategy: Go around stabbing people with his spear and being awesome. If Caesar asks him his strategy, he will reply with his motto, "Float like a mockingjay, sting like a tracker jacker." He will likely throw his shirt into the crowd during the chariot ride to make himself feel awesome.
Token: Copy of Twilight- his plan is to steal Chaff's liquor, soak the book in it, then light it on fire while he throws it off the roof of the Training Center
History: He claims to have been unofficially awesome since age 0. Has had a plan for the Games since he was 6 (see Strategy.) He acts awesome at home, too, but other than his slightly weird personality he is pretty much normal.
Kwanito44's First Hunger Games: Somewhere between 3rd/24 and 10th/24
Thena.airice14's 34th Hunger Games: 9th/24
Katelyn.danita's 100th Hunger Games: 11th/24 (These ones may be slight overkill, but if you're looking for an example of JJJ's annoyingness [as well as a good laugh] then these games are probably a good place to start.
YoungGuy5's Insanity Games: 139th/141- Stabbed by Bailey Anderson during bloodbath.
Oblivion1001's 79th Hunger Games:
Angry birds12's End Games:
His original name was Will Anderson until Beetee19 figured that his given name did not properly suit his 'I'm awesome and I don't care about anything' personality.