Slightly embarrassing confession - ds STILL uses his activity ring
. Got it from Tesco, about £30, he loved it to play in and use all the toys when he was your lo's age, but now he uses it to lounge about in when he's drinking his milk (and having his daily episode of Balamory
). So, if your lo is anything like mine, it'll be worth it.
Also, at that age, ds loved his Bumbo seat - he could sit and watch us, made him feel part of things, IYKWIM. Also, I'm convinced it helped him sit up properly. They're not cheap from the shops, but I got a good one (second hand but very clean) from Ebay. I also used it (and still do) as a portable seat for going out - to friends houses, or instead of yucky restaurant high chairs. Really easy to use, carry and clean. (I promise I don't sell them, I just can't recommend them highly enough
).
How about a doorway bouncer (I don't know what a jumperoo is, is that the same thing?).