Sorry for my bad JavaScript, it is my first try to use this language.

telekom-backlog-filter.js

// ==UserScript==
// @name        Backlog Filter
// @namespace   myproject.telekom.de
// @description MyProject ein paar Buttons schenken, mit denen sich Backlogs filtern lassen
// @include     https://myproject.telekom.de/pi/rb/master_backlogs/hmp
// @require     http://code.jquery.com/jquery-1.9.1.min.js
// @version     3.15
// @grant none
// ==/UserScript==

function filterTo(text) {
	return function() {
        window.jQuery('.backlog').hide().filter(function(){ 
            return window.jQuery(this).find('.name').text().match(text);
        }).show(); 
    };
}

var $h2 = window.jQuery('#content > h2');
var labels = [
    "S&C",
    "ProSyst",
    "B&R",
];
var filters = [
    /Setup/i,
    /mPRM|ProSyst/i,
    /Billing|Back-?End/i,
];

for (var i=0, label, filter; label = labels[i], filter = filters[i]; i++) {
    window.jQuery('<button>')
        .text(label)
        .click(filterTo(filter))
        .insertAfter($h2);
}

window.jQuery('<button>')
    .text("Alle")
    .click(function() {
        window.jQuery('.backlog').show();
    })
    .insertAfter($h2);

// Activate to pre-select a specific filter
//window.jQuery("button:contains('B&R')").click();

telekom-myproject-keepalive.js

// ==UserScript==
// @name        MyProject KeepAlive
// @namespace   myproject.telekom.de
// @description Make a request every 5 minutes to prevent the session from timing out
// @include     https://myproject.telekom.de/*
// @require     http://code.jquery.com/jquery-1.9.1.min.js
// @version     3.14
// @grant none
// ==/UserScript==

function keepAlive() {
    window.jQuery.ajax({ method: 'get', url: 'https://myproject.telekom.de/pi/projects?' + (Math.random()) })
        .always(function() {
            setTimeout(keepAlive, 5 * 60 * 1000);
        });
}

keepAlive();

telekom-owa-keepalive.js

// ==UserScript==
// @name        OWA KeepAlive
// @namespace   myproject.telekom.de
// @description Make a request every 5 minutes to prevent the session from timing out
// @include     https://owa.t-online.net/owa/
// @include     https://owa.t-online.net/owa/*
// @require     http://code.jquery.com/jquery-1.9.1.min.js
// @version     1.34
// @grant none
// ==/UserScript==

function keepAlive() {
    window.jQuery.ajax({ method: 'get', url: 'https://owa.t-online.net/owa/?' + (Math.random()) })
        .always(function() {
            setTimeout(keepAlive, 1000);
        });
}

keepAlive();

telekom-save-login.js

// ==UserScript==
// @name        OWA/MyProject AntiSecurity
// @namespace   myproject.telekom.de
// @description Form-Speicherschutz aufheben für MyProject und OWA
// @include     https://myproject.telekom.de/pi/login
// @include     https://owa.t-online.net/owa/auth/logon*
// @version     1.34
// @grant none
// ==/UserScript==

var elems, i, l;

elems = window.document.forms;
for (i=0, l=elems.length; i < l; i++) {
    elems[i].setAttribute('autocomplete', 'on');
    elems[i].autocomplete = true;
}

elems = window.document.getElementsByTagName('input');
for (i=0, l=elems.length; i < l; i++) {
    elems[i].setAttribute('autocomplete', 'on');
    elems[i].autocomplete = true;
}

• Filtering is now done based on RegEx instead of simple text match.
• Added button labels (can be different from filter conditions).
• Removed Shop, Portal, SDK (they are no longer in the same project as S&C, mPRM, B&R).
• Changed unsafeWindow to just windowso as to avoid problems in Chrome with Tampermonkey.
• jQuery require added to each script.