Features

Whitelist Applications

Micromanager will only let you use applications you added to your whitelist.

The free version lets you select one application to whitelist. Pro users can select any number of apps.

Recently opened applications: Micromanager automatically lists currently opened apps so that you can get started faster. Click the add recently opened apps button to refresh the list with applicaions you opened after running Micromanager.
Add exe file: If the list doesn't contain the app you want to whitelist, click this button to browse to the file and add it manually.
Import/export from file Pro Only: The export to file button lets you save the selected applications so that you can quickly import them again in a new session.

Durations of the Block

Here, you'll need to select how long you want the block to last.

Timer: The most common option is to have a time based block. Select predefined times or a custom date/time you want your block to last for. Blocks can last anywhere from 1 minute up to 1 day, for the free version. Pro users don't have the 1 day duration limit.
Restart: Selecting this option will only allow apps in your whitelist to be opened until you restart your computer. This is a great way to add some flexibility around the block in case you need to access something in an emergency.

Take a Break Pro Only

You aren't a robot. Take some breaks while working to help keep you refreshed and focused for when it's time to get stuff done.

Pomodoro timers: Pomodoro timers alternate the block on and off while you work to allow for breaks at predefined times.
Allowances: Allowances, on the other hand, let you use other apps until the allowance is used up. At which point, your block will start.

Once you start, you can't go back.

Micromanager is designed to be hard to get around. Once you start a block, there's not much you can do except to work using whitelisted apps.

You won't be able to uninstall, change the time or end processes using the task manager to prematurely end the block.

Blocking Settings

To get to this tab, click the Settings tab at the top.

Blocking: These options let you choose how strict the block is, like whether Micromanager will minimize non-whitelisted apps or force close them completely.
Notifications: Under this tab, you can choose whether or not you want to see a notifications for certain events (like an app being closed, or your block ending).

Keeping track of time.

Once a block is started, you'll be able to keep track of how much time is left before your block is over. Your allowance and breaks remaining will also be listed here.

Screenshot of countdown while a block is active