Twitter’s API issues have frustrated developers in each of Twitter’s new API access tiers. Those with Basic or Pro plans — paying $100 and $5000 a month for API access, respectively — have experienced unannounced changes to their plans, numerous bugs, and often receive zero customer support. And developers shelling out for Twitter’s Enterprise API Plan, which starts at $42,000 per month, are experiencing sudden outages and disappointing service considering the money they’re paying.
Twetbot (which I used personally and loved), Tweetdeck, and Twitterrific to name a few. They have been around for a while (some over a decade).