Add-PSSnapin microsoft.sharepoint.powershell
function CreateSPListItems()
{
    $sites = Get-SPSite
    if($sites.count -eq 0)
    {
        Write-Warning "There is no site available."
        CreateSPListItems
    }
    else
    {
        Write-Host "Choose the site:" -ForegroundColor Yellow
        for($i=0;$i -lt $sites.count;$i++)
        {
            $tip = "["+$i+"]."+$sites[$i].url
            Write-Host $tip
        }
        $choice = Read-Host "Enter the number before"
        $tip = "You chose "+$choice+". "+"The site you chose is '"+$sites[[int]$choice].url+"'"
        Write-Host $tip -ForegroundColor Green
        Write-Host "Choose the web:" -ForegroundColor Yellow
        $webs = $sites[[int]$choice].AllWebs
        for($i=0;$i -lt $webs.count;$i++)
        {
            $tip = "["+$i+"]."+$webs[$i].url
            Write-Host $tip
        }
        $choice = Read-Host "Enter the number before"
        $tip = "You chose "+$choice+". "+"The web you chose is '"+$webs[[int]$choice].url+"'"
        Write-Host $tip -ForegroundColor Green
        $lists = $webs[[int]$choice].lists
        if($lists.count -eq 0)
        {
            Write-Warning "There is no list available."
            CreateSPListItems
        }
        else
        {
            Write-Host "Choose the list:" -ForegroundColor Yellow
            for($i=0;$i -lt $lists.count;$i++)
            {
                $tip = "["+$i+"]."+$lists[$i].title
                Write-Host $tip
            }
            $choice = Read-Host "Enter the number before"
            $tip = "You chose "+$choice+". "+"The web you chose is '"+$webs[[int]$choice].url+"'"
            $list = $lists[[int]$choice]
            $tip = "The list you chose is '" + $list.title +"'"
            Write-Host $tip -ForegroundColor Green
            $amount = Read-Host "How many items do you want to create"
            $titleEp = Read-Host "Give an example of the item title, such as 'tylan'"
            for($i=1;$i -le $amount;$i++){
                $random = Get-Random 10000
                $sign = $date.month+$date.day+$date.hour+$date.minute+$date.second+$random
                $newItem = $List.Items.Add()
                $newItem["Title"] = $sign.ToString() + $titleEp + "TestData"
                $newItem.Update()
            }
            $tip = "Items have been created successfully under the list '"+$list.title+"'."
            Write-Host $tip -ForegroundColor Green
            $choice = Read-Host "Press 'c' to continue"
            if($choice -eq 'c')
            {
                CreateSPListItems
            }
        }
    }
}
CreateSPListItems