I like the Overball for babies older than 12 weeks old upto pre-crawlers.
The Sassy Mirror for TummyTime is another great choice
This light up toy is also musical.
The Sassy Rattle is quite handy too.
My favorite tummytime mat that is easy to store and clean and is reversible.
The ones below are also other good options for travel time tummytime.
A book for baby
For rear facing babies that don’t like their carseats, this may help them