Article: Its app icon resembles the word "imo" inside of a speech bubble on a white background. If you aren't signed into imo on your computer, you'll need to sign in using your phone number. It's in the upper-left side of the window. Look for a person whom you want to block in the CONTACTS window on the left side of the window, then click their name. This opens a chat window with the person. Doing so will prompt a drop-down menu.  If your mouse doesn't have a right-click button, click the right side of the mouse, or use two fingers to click the mouse. If your computer uses a trackpad instead of a mouse, use two fingers to tap the trackpad or press the bottom-right side of the trackpad. It's at the bottom of the drop-down menu. This will remove the person from your contacts. It's at the top of the person's profile page. This will add the person to your "Blocked Contacts" list, meaning that they won't be able to contact you on imo.

What is a summary?
Open imo. Click the CONTACTS tab. Select a person to block. Right-click the person's name. Click Remove from Contacts. Click Yes when prompted. Click Block.