Dreamcolor

You can write a simple post in frontend without login to backend. 
You can easily to post something like Twitter. Write Sideblog is also good idea.

Quick Press Widget

You can write a simple post in frontend without login to backend.

Paolo

AyeCode

Stiofan

ReCaptcha addon for <a href="https://wordpress.org/plugins/userswp/" rel="ugc">UsersWP</a>.
The UsersWP ReCaptcha plugin allows you to implement a super security captcha into forms like 
registration, login forms. UsersWP Re-Captcha protects your site against spam, malicious registrations 
and other forms of attacks where computers try to disguise themselves as a human.
UsersWP Re-Captcha provides some of the smartest anti-spam security by protecting your site against spam and 
malicious registrations available today for WordPress.
<a href="https://www.google.com/recaptcha/" rel="nofollow ugc">Learn how reCAPTCHA works</a>
<h3>Requirements</h3>
<ul>
<li>You need the Google reCAPTCHA keys from <a href="https://www.google.com/recaptcha/admin#whyrecaptcha" rel="nofollow ugc">here</a>.</li>
</ul>

Quick Press Widget vs UsersWP – ReCaptcha