Tomkins recently reached the milestone and discussed the achievement with West Ham TV.
And, after watching the video of Tomkins' reflections, ex-Hammer Collison tweeted his former club that he was 'over the moon' for the centre-back after his 'amazing achievement.'
"I'm very sad for him but it's what happens," Ipswich boss Mick McCarthy said of the midfielder when he left the club.
"I thought he was really well worth a chance because when he came in, he looked the part in training. He's a great lad to have around the place as well, a really good pro - but it's not worked out."