So, the Ring of Jumping allows an attuned user to cast Jump on themselves, and:
Once on each of its turns until the spell ends, that creature can jump up to 30 feet by spending 10 feet of movement.
Now, as the ring makes no mention of limited uses or a recharge timeframe, one can (in the absence of other information) assume that an attuned user of the ring can recast the spell as many times as he/she likes. This means that an otherwise normal human could have a travel speed of 50 on the open road or under a high ceiling, making for some unusual combat applications.
This thought brought on a rather comedic visualization of someone in a suit of full plate jumping from place to place like The Hulk of the comics.