zaus

Exposes file upload/attachments to the regular service mapping of <a href="https://wordpress.org/plugins/forms-3rdparty-integration/" rel="ugc">Forms 3rdparty Integration</a>.
From discussion at https://github.com/zaus/forms-3rdparty-integration/issues/40.

Forms: 3rd-Party File Attachments

Add file upload processing to Forms 3rdparty Integration.

webheadcoder

Add multi-step forms to Contact Form 7 with full data persistence between pages and a single email on final submission. Upgrade to Pro to submit 5MB forms through sessionStorage, conditional step-skipping, and priority support.
The Original Contact Form 7 Multi-Step Plugin
Since 2012, this has been the go-to multi-step solution for Contact Form 7 users. It’s built for reliability and trusted on thousands of sites. Split your CF7 form across multiple pages, preserve data between steps, and send one complete email at the end.
It’s been running quietly on thousands of sites through every major WordPress and CF7 release. If you need multi-step forms with CF7, this is where most people start.
See it in action at <a href="https://webheadcoder.com/contact-form-7-multi-step-form/" rel="nofollow ugc">https://webheadcoder.com/contact-form-7-multi-step-form/</a>
Requires <a href="https://wordpress.org/plugins/contact-form-7/" rel="ugc">Contact Form 7</a> (5.2 or above) by Rock Lobster Inc. (Takayuki Miyoshi).
Usage
<ol>
<li>
Create one page or post for each step in your multi-step form process. If you have 3 steps, create 3 pages/posts. You will need the urls to these when creating your forms.
</li>
<li>
Create a Contact Form 7 form.
</li>
<li>
Place your cursor at the end of the form.
</li>
<li>
On the “Form” tab of the Contact Form 7 form, click on the button named “multistep”.
</li>
<li>
In the window that pops up, check the checkbox next to “First Step” if this is the first step of your multi step forms. If this is your last step in the multi step forms, check the “Last Step” checkbox. All other checkboxes are optional.
</li>
<li>
The Next Page URL is the url that contains your next form. If this form is the last step, you can leave the URL field blank.
</li>
<li>
Click “Insert Tag”
</li>
<li>
Save your completed form and place the form’s shortcode into the appropriate Page/Post you created in step 1.
</li>
<li>
Repeat for each form in your multi-step form process.
</li>
<li>
On the last step, you probably would want to send an email. Make sure to check the “Send Email” checkbox in step 5. On the Mail Tab, simply enter the mail-tags as you normally would. For example if your first form has the field <code>your-email</code> you can include <code>[your-email]</code> in the Mail tab on your last form. Note: CF7 will see this as an error because <code>your-email</code> may not be displayed on the current form. You can safely ignore this error.
</li>
</ol>
Multistep Tag Options
<ul>
<li>
Name – The name of this multistep form-tag. This is required, but is currently not being used.
</li>
<li>
First Step – Besides marking the first step of your multistep forms, this allows any form to act as the first step and show when no previous data has ben submitted. This is useful when you want some users to skip the first step.
</li>
<li>
Last Step – Besides marking the last step of you multistep forms, this clears the data from user’s browsers. Once they submit this form they won’t see their data populating the forms anymore.
</li>
<li>
Send Email – If this is checked the form will send an email like a normal Contact Form 7 submission.
</li>
<li>
Skip Save – If you use Flamingo or CFDB7 to save submissions to the database this prevents saving this form submission.
</li>
<li>
Next Page URL – This is the URL your users will go to after the form is submitted.
[multistep multistep-123 last_step send_email skip_save “/thank-you”]
</li>
</ul>
Additional Tags
<pre><code>[multiform "your-name"]
</code></pre>
The <code>multiform</code> form-tag can be used to display a field from a previous step. Replace <code>your-name</code> with the name of your field. This is only for use on the Form tab, this tag will not work in the Mail tab.
<pre><code>[previous "Go Back"]
</code></pre>
The <code>previous</code> form-tag can be used to display a button to go to a previous step. Replace <code>Go Back</code> with text you want to show in the button.
Messages Tab 
When a visitor to your site visits the 4th step in your multi step form without filling out the 1st step, the message “Please fill out the form on the previous page.” will be displayed. You can change this on each form in the Messages tab.
What this plugin DOES NOT do:
<ul>
<li>
This plugin does not support file uploads on every form. If you need to use file uploads make sure to place it on the last step.
</li>
<li>
This plugin does not load another form on the same page. It only works when the forms are on separate pages. Many have asked to make it load via ajax so all forms can reside on one page. This plugin does not support that.
</li>
</ul>
PRO Version 
If you expect to have a lot of data submitted through your multi-step forms, the Pro version may be able to help you better. The PRO version uses Session Storage so it is able to handle roughly 1,000 times more data for your multiple forms. In total it can handle about 5MB vs 4KB in the free version. Currently the Pro version REQUIRES the WordPress REST API and Contact Form 7 AJAX Submission to be enabled.
Another feature the Pro version offers is the ability to skip steps with the “Contact Form 7 – Conditional Fields plugin”. <a href="https://webheadcoder.com/contact-form-7-multi-step-forms/#pro" rel="nofollow ugc">Learn more here.</a>

Contact Form 7 Multi-Step Forms

After another well-known contact form plugin stopped working I needed a different multi-page form solution. CF7 with this plugin fit the bill.

Does what it needs to do.

Enables the Contact Form 7 plugin to create multi-page, multi-step forms.

Forms: 3rd-Party File Attachments vs Contact Form 7 Multi-Step Forms