Here are some of the powerful plugins in wordpress for free that do the complicated tasks which you may need to perform manually.
1. CSV2POST :- This plugin helps you to convert your csv file’s data into blog posts. This plugin is very user friendly and simple, not only create posts also provide additional functionality like create custom fields, custom post type with featured image, choose your blog layout, create tags and category and many others.
This plugin convert your csv file’s each row into a very nice blog post.
2. WP SHOW-HIDE :- If you want to hide/show some content from your blog post or page with toggle effect than this is the best plugin for your use. Use simple shortcode and place your content between in this shortcode, with very simple functionality this shortcode hide your content from direct view of readers.
3. CAPABILITY MANAGER ENHANCED :- This is one of the best plugin using for define the capability of the user , it helps to give the different privilege to the register user like post a blog, create a page and more as per your choice. Here you can also create your own user role.
4. REGISTER PLUS REDUX :- This plugin help us to build safe registration functionality in your site. This plugin provides email verification, admin verification functionality, custom login/registration CSS and many other advance option improve your sites registration functionality.
5. USER SUBMITTED POSTS :- If you want to embed guest post facility in your site then this is plugin is very useful. It allows users to submit their posts from front end.
No user registration required.You can select the fields you want to appear on the submission form and hide any field that you don’t want users to see. You can choose a default author for all user submitted content.