Vocabulary Testing Program 6 (VTP6) is a free to use open-source online platform to help students revise vocabulary.
VTP5 is the app-based predecessor to VTP6. It was last updated in 2015, and is the successor of VTP4, which was last updated around 2000. No information is available online about the predecessors of VTP4. VTP6 is the first online VTP, and therefore the first VTP which can be used on a phone.
Parandum, created in 2021 and last updated in 2022, was meant to be the online successor of VTP5. However, after the creator finished their A Levels (having used Parandum as a Computer Science NEA), the repository was archived and the website stopped working.
The main difference from VTP5 is that VTP6 is online and can therefore be accessed from a phone. Other differences include the Match mode in VTP6, and also having some sets built-in.
The main difference from Parandum is that VTP6 actually works. However, when Parandum was working, it lacked a Hangman and Match mode (VTP6 has both).