Bloom allows you to import and export contacts in a .csv file.
Importing:
Contacts > Filter > Import Contacts
Inside the Import Contacts overlay, select the Upload your CSV file and browse through the files on your device to choose the desired CSV file.
Once the file is uploaded, you'll see the multiple value fields that you have the choice of assigning to your contacts. The fields will be ignored unless you make a selection to assign a particular value to that column. Only those selected will be imported.
Keep in mind, your CSV file is required to contain each contact’s email address, first and last name in order to import. Double check to ensure that all headers correlate to the correct fields.
Once you're all set, hit Import and you're good to go!
Exporting:
Settings > Exporting > Contact Data