Blink has different tiers of membership that "buy" you different hourly rates once they start charging a fee, although it may be up to the individual operators as to whether the chargers stay free or cost $. The $2/hr fee is the no-strings-attached rate, i.e. no annual fee, etc.
Yes, the $1/hr fee is with the top tier membership. The annual fee is temporarily waived, though they haven't said for how long this will last. The only controversy with grabbing this freebie now is that to do so you must also agree to extend your residential agreement if you have one. As EV Project deadlines slip and are extended though, I don't mind giving my charging data to the EV Project for a while longer. I'd give it to them for as long as it might help actually.
Some things to keep in mind when using a Blink station:
1. If you're set up for deferred charging, you'll need to over-ride when you plug into a Blink station. See your owners manual for several ways to do this.
2. You should consider disabling the alarm if/when somebody disconnects your car from a Blink charger when the doors are locked. See the owners manual.
3. Related to #2, think about whether you want to create a dash placard for, e.g. Leaf/Tesla owners who desperately need a charge at the station you're using (telling them whether you're okay if they disconnect you or whatever).
Thanks for mentioning that. (I don't think I've seen anyone pay any attention to a car alarm in the past 20 years, they're so common.

My placard copied from Plugin America has hours across the top, and I put a paper clip showing the time I expect to have all the charge I need. Afterwards, though it might be nice to get more charge, you're welcome to unplug me if you need it. That way you don't have to learn how to read the charging indicator lights on my Leaf and vice versa, and I can share the plug before I get a full charge if (as usual) I don't really need that much.
Most people don't use the placards around San Diego. The only time I've shared it was with a Volt. I already had enough charge to drive home with plenty of range to spare and the placard told him he was welcome to take the plug. Thus we were both able to drive home purely on clean electric power.
4. On the Blink website you can select the kind of notifications you want. I limit mine to when the car is disconnected (which can be either charge completed or plug removed).
The Blink app for Android, and I expect for iPhone also, puts an icon in the notification bar you can pull down to view charging status. The notification reappears whenever charging status changes. This is in addition to whatever notifications you set the car to provide, and for me it's plenty.