Labfolder offers users two Apps for data validation, Sign & Witness and Signature Workflows:

• The free Sign & Witness App allows you to sign and request 1 more witness.
• Signature Workflows, however, is a paid upgrade designed to create complex validation workflows, including multiple witnesses and the option to comment on approval or rejection actions.

Labfolder's lavishly customisable Signature Workflows App offers the following advantages:

• An unlimited number of signatories (witnesses).
• Custom approval or rejection statements to an entry.
• The ability to move entries to other projects (upon the rejection or final approval of an entry).
• Electronic signatures that comply with FDA CFR part 11.

Tip: There is actually a blog on this topic that you may find inspiring.