Arsenal remain fourth, but they are ahead of fifth-placed Chelsea only on goal difference as the race to qualify for Champions League heats up.
The 35-year-old also wrote about his new career development on social networking sites Twitter and Instagram.
The new deal will see England defender Phil Jagielka remain at Goodison Park until the summer of 2018.
Everton edged out Southampton 1-0 to leave the Saints trailing fourth placed Manchester City by eight points with just seven games to play.
Everton defender Phil Jagielka says England's players will all have points to prove when they tackle old rivals the Republic of Ireland in an end-of-season friendly at Wembley Stadium on Wednesday.
Everton had announced earlier that Jagielka had signed a two-year contract extension that will keep him at Goodison Park until 2017.
Jagielka joined Everton from Sheffield United in 2007 and has since made close to 200 appearances in all competitions.
England may appear to be in turmoil having only hired a coach a month ago and losing three key players to injury in the last 10 days but Johnny Heitinga believes all is not doom and gloom.
Gareth Barry was ruled out of the European Championship on Monday because of a stomach injury, robbing England of one of its two holding midfielders less than two weeks before the start of the tournament.
England international Phil Jagielka was left on the Everton substitutes bench for Saturday's FA Cup semi-final against Liverpool at Wembley.
Everton manager David Moyes says defender Phil Jagielka could be missing for up to six weeks after damaging medial ligaments in his right knee in the Premier League loss to Bolton.