Antpool, it's free but you need to wait until they mine a block and even then it might not confir your transaction because of the sheer amount of backlog they have on their acceleration system right now. Still worth a shot though. Link:
https://www.antpool.com/user/prioritiseTransaction.htm?m=savePrioritiseTxOf course Viabtc has that limit, it's annoying and it's hard to race ahead of people who are just camping there with bunches of TXID to submit.
If you are willing to pay for acceleration and your transaction has high value then try btc.com or btcspeedy. The latter i'm not sure whether it works or not, but btc.com definitely works. Do NOT use confirmtx, they are confirm
scam.