Before you Leap by Les Lynam is a wonderful YA time travel novel with many other scifi ideas included. Les gives us ideas of future technology as well as an elegant time travel methodology – and how strained relationships between a Grandfather and a 5 times great grandson can be!
Josh Anderson’s “The Tunnel” is Book 1 of the Time of Death series for young adults. Time travel is via a “silk blot” which is a really original method of time travel, providing an entrance (and exit) to a tunnel complete with ladders and rungs marking the year. Lots of interesting threads, but sadly there’s no closure, just a “To be continued…”.
Bridgevine (John Feldman) is a very easy read with a simple plot involving time travel, but obvious time travel questions are ignored rather than left open. Repetition and over explanation, plus an immature main character lead me to believe this is a novel aimed at young adults or to be taken on holiday. On the positive side there are some nice examples of how and why a time machine can be used.